The present invention relates to an electrical connector of the type in which the contacts are inserted into and extracted from the rear of the connector insulator and, more particularly, to an insulator for such a connector embodying integral contact retention cones and a method and apparatus for making the same.
It is desirable in an electrical connector to have the insulator therein in which the contacts are mounted formed of a one-piece, homogeneous dielectric material. U.S. Pat. No. 4,114,976 to Selvin et al. discloses methods for mounting metal contact retention clips in onepiece insulators. In one such method, as depicted in FIGS. 1 and 2 of the patent, the insulator is molded around a single core pin for each contact passage having an aluminum sleeve mounted over the pin. After the core pin is removed from the molded insulator, the sleeve is removed by etching with a chemical solution. Thus, there is provided in the wall of each contact passage an annular groove having shoulders at its opposite ends which positively retain a contact retention clip that is snapped into the groove through the rear of the contact passage. The core pin has a small-diameter forward end which allows a "closed entry" to be formed at the front of the passage when the insulator is molded around the pin. The closed entry provides an inwardly extending annular flange at the front of the contact passage which limits forward movement of the contact therein. In addition, if the contact is a socket contact having spring beams, the flange will prevent the beams from being damaged when a mating pin contact or electrical probe is inserted into the contact passage from the front of the insulator.
U.S. Pat. No. 3,165,369 to Maston and U.S. Pat. No. 3,727,172 to Clark disclose electrical connectors utilizing insulators having integral contact retention cones in the contact passages thereof. Each contact passage and cone therein is formed by the use of a pair of core pins in a mold having end regions which are shaped to define the contact retention cone when a dielectric material is molded around the pins. After the material hardens, the core pins are separated to provide a through passage with a contact retention cone directed toward the front of the insulator thus formed. In order to provide entry for the contact passage, a second insulator must be mounted on front of the first mentioned insulator. The second insulator is adhered to the first insulator by a suitable adhesive or cement. The resulting two-piece insulator has the disadvantage that the boundary line between the front and rear insulator parts produces a potential electrical leakage path which could cause shorting between adjacent contacts in the insulator.
It is the object of the present invention to provide a one-piece, homogeneous electrical connector insulator embodying integral contact retention cones in contact passages having closed entries, and a method and apparatus for manufacturing the same.